World War II began in Europe on the morning of September 1 when one-and-a-half million German troops stormed into Poland in a high-speed armored wave. The German leader Adolf Hitler, addressing the Reichstag, insisted that the Polish army had started the shooting, and declared himself “determined to eliminate from the German frontier the element of insecurity.…”

Britain and France both declared war on Germany two days later but were unable to do anything to save Poland from the German blitzkrieg. With the Russian army invading from the east at Germany’s invitation, the antiquated Polish military lasted less than a month, and its government was forced to flee the country.

Other nations, among them the United States, Italy, and Spain, declared their neutrality. The American proclamation of neutrality came on September 5, and President Roosevelt, in an October fireside chat, offered vehement reassurances about his position: “In and out of Congress we have heard orators … beating their breasts proclaiming against sending the boys of American mothers to fight on the battlefields of Europe. That I do not hesitate to label as one of the worst fakes in current history. It is a deliberate setup of an imaginary bogy.”

∗On September 15 Westinghouse engineers in Pittsburgh, Pennsylvania, trapped and measured a bolt of natural lightning for the first time in history. They estimated that the bolt would have been able to power forty thousand electric lights.